This invention relates to bags for containing bulk material, particularly, although not exclusively, material which consists of lumps, granules and/or particles which are not larger than 2 centimeters. Such bags may be used, for example, for transporting clay in bulk.
Large bags for containing bulk material are already known but many of these are either very expensive or have a tendency to fail catastrophically when under load, as, for example, when the filled bag is lifted by a crane.
British Patent Nos. 1,431,581 and 1,484,984 describe bags which have four separate lifting loops disposed around the top. Each loop has two legs each of which is secured to the fabric of the bag by folding a portion of the fabric to a substantially S-shaped configuration and then stitching through the three thicknesses of fabric and the leg, which may be placed either on an exposed surface of the folded portion or between the folds. This arrangement has the disadvantage that when the bag is under load the fabric has a tendency to fail catastrophically at or below the level of the lower ends of the legs of the loops, allowing the loaded bag to fall away as a body.